Suspension compliance to reduce frame loading

ABSTRACT

A harvesting system includes a header pivotally attached to a combine. The header includes a center section to which a left wing and right wing are pivotally attached. A suspension system of the harvesting system includes first and second engageable states that enable dynamic wing behavior and reduce structural load. The first state corresponds to a harvesting configuration of the header in which the wings are allowed to pivot to allow the header to follow changes in terrain. The second state corresponds to a configuration in which the header is elevated relative to the ground. In the second state, the ability of the wings to pivot is minimized as compared to the first state, which allows the header to be maintained in a substantially flat configuration while minimizing the amount of dynamic load imparted by the header on the combine during non-harvesting transport of the header.

FIELD OF THE DISCLOSURE

The present application claims the benefit and priority under 35 U.S.C.§ 119(e) to U.S. Provisional Application No. 62/693,278, titled“SUSPENSION COMPLIANCE TO REDUCE FRAME LOADING,” filed Jul. 2, 2018,which is incorporated herein in its entirety.

BACKGROUND

Crop harvesting is commonly performed by a harvesting system comprisinga combine harvester (“combine”) equipped with a removable headerdesigned for harvesting crops. In an attempt to increase the throughputof such harvesting systems, combines are being paired with increasinglywider headers. However, although the increased span of such widerheaders may improve throughput by increasing the rate at which groundcan be covered by the harvesting system, the increased width of theheader may result in a decrease in crop yield efficiency. In particular,given the rigid, flat configuration of headers typically used in suchharvesting systems, the increased inability of wider, rigid frame headerto conform to variations in terrain often results in a decrease in theamount of crop that is harvested as the harvesting system travels overuneven terrain.

Additionally, increasing the width of the header of a harvesting systemoften increases the structural loads imparted by the heavier, widerheader onto the combine. As a result, many combines that are used insuch wider header harvesting systems incorporate reinforced combinestructures configured to support the added weight of a wider header andto withstand and resist the increased dynamic loads that such widerheaders impart. In addition to increasing the material costs required tomanufacture such reinforced combines, the added mass of such reinforcedcombines also typically increases the costs of operating the harvestingsystem.

SUMMARY

One implementation of the present disclosure is a harvesting system thatincludes a harvesting combine and a harvesting header. The harvestingheader includes a center section, a left wing hingedly attached to thecenter section, and a right wing hingedly attached to the centersection. The header is pivotally attached to a support structure of theharvesting combine. The header is configured to pivot relative to thesupport structure to transition between a first position in which theheader is at least partially supported by a ground surface and a secondposition in which the header is entirely supported by the combine. Whenthe header is in the first position, the ability of the left wing andthe right wing to pivot upward or downward relative to the centersection is constrained to a first operating range. When the header is inthe second position, the ability of the left wing and the right wing topivot upward or downward relative to the center section is constrainedto a second operating range. The first operating range is greater thanthe second operating range.

According to some embodiments, the second operating range is greaterthan 0°. According to some embodiments, the first operating rangecorresponds to a range that extends between approximately 5.0° upwardsand approximately 5.0° downwards as measured relative to the centersection. According to some embodiments, the second operating range isapproximately 20% of the first operating range. According to someembodiments, the second operating range corresponds to an angulardisplacement of approximately 2.0°.

According to some embodiments, the harvesting system further includes avariable spring suspension system configured to selectively constrainthe pivoting of the left wing and right wing relative to the centersection to either the first operating range or the second operatingrange.

One implementation of the disclosure is a harvesting system including aharvesting combine, a harvesting header and a suspension system. Theharvesting header includes a center section, a left wing hingedlyattached to the center section, and a right wing hingedly attached tothe center section. The suspension system has an engageable firstvariable state and an engageable second variable state. The secondvariable state is different than the first variable state. When theheader is in a harvesting position and the first variable state of thesuspension system is engaged, the left wing and right wing are allowedto pivot relative to the center section. When the header is elevatedentirely off of the ground, the second variable state of the suspensionsystem is automatically engaged and the left wing and the right wing areallowed to pivot upward or downward relative to the center section.

According to some embodiments, the degree to which the left wing andright wing are allowed to pivot relative to the center section when theheader is in the harvesting position is greater than the degree to whichthe left wing and right wing are allowed to pivot when the header iselevated entirely off of the ground.

According to some embodiments, when the first variable state of thesuspension system is engaged, the right wing and left wing are allowedto pivot within a range of approximately 5.0° upwards and approximately5.0° downwards as measured relative to the center section. According tosome embodiments, when the second variable state of the suspensionsystem is engaged, the right wing and left wing are allowed to pivotwithin a range that corresponds to an angular displacement ofapproximately 2.0°. According to some embodiments, when the secondvariable state of the suspension system is engaged, the left wing andright wing are allowed to pivot within a range that is approximately 20%less than the range within which the left wing and right wing areallowed to pivot when the first variable state of the suspension systemis engaged.

According to some embodiments, directly subsequent to the secondvariable state of the suspension system being engaged, the position ofthe left wing relative to the center section corresponds to the positionof the left wing relative to the center section directly prior to thesecond variable state of the suspension system being engaged, and theposition of the right wing relative to the center section corresponds tothe position of the right wing relative to the center section directlyprior to the second variable state of the suspension system beingengaged.

According to some embodiments, the suspension system includes a fluidcylinder fluidly connected to an accumulator and a valve selectivelyopenable to permit flow between the fluid cylinder and the accumulator.The suspension system is configured to engage the second variable stateby closing the valve to block flow between the fluid cylinder andaccumulator. According to some embodiments, the fluid cylinder isfluidly connected to the accumulator by an attenuation hose. Accordingto some embodiments, fluid from the fluid cylinder is configured to flowinto the attenuation hose when the second variable state of thesuspension system is engaged.

One implementation of the present disclosure is a harvester systemincluding a harvesting combine, and articulated header, and a variablespring suspension system. The articulated header is defined by at leasta first section and a second section. The variable spring suspensionsystem has a first variable spring state and a second variable springstate. In the first variable spring state, the suspension system isconfigured to allow the first section and second section to pivotrelative to one another according to a first range of motion. In thesecond variable spring state, the suspension system is configured toallow the first section and second section to pivot relative to oneanother according to a second range of motion. The first range of motionis greater than the second range of motion.

According to some embodiments, the header is pivotally attached to thecombine and configured to move between a first position in which atleast a portion of the header weight is supported by the ground and asecond position in which an entirety of the header weight is supportedby the combine. The suspension system is configured to activate thefirst variable spring state when the header is in the first position andto activate the second variable spring state when the header is in thesecond position.

According to some embodiments, the harvester system further includes acontrol system having an automatic header height control mode. Thesuspension system is configured to automatically activate the secondvariable spring state in response to the header height control modebeing deactivated.

According to some embodiments, the suspension system includes a fluidcylinder fluidly connected to an accumulator and a valve selectivelyopenable to permit flow between the fluid cylinder and the accumulator.The suspension system is configured to activate the second variablespring state by closing the valve to block flow between the fluidcylinder and accumulator.

According to some embodiments, the suspension system includes a firstcoiled spring and a second coiled spring. The first coiled spring isconfigured to impart a greater spring force than the second coiledspring. The suspension system is configured to selectively engage thefirst coiled spring to impart a spring force on the first section whenthe header is in the second position.

Those skilled in the art will appreciate that the summary isillustrative only and is not intended to be in any way limiting. Otheraspects, inventive features, and advantages of the devices and/orprocesses described herein, as defined solely by the claims, will becomeapparent in the detailed description set forth herein and taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C illustrate a harvester in a harvesting configurationtravelling over different types of terrain, according to someembodiments.

FIG. 2 is a simplified block diagram illustrating a top view of aheader, according to some embodiments.

FIG. 3 illustrates a harvester in a non-harvesting transportconfiguration, according to some embodiments.

FIG. 4 is a simplified diagram illustrating a suspension system,according to some embodiments.

FIGS. 5A-5C are simplified general block diagrams illustrating a blockervalve, according to some embodiments.

FIG. 6A is a simplified general block diagram illustrating a suspensionsystem during a harvesting configuration of a harvester, according tosome embodiments.

FIG. 6B is a simplified general block diagram illustrating a front viewof a header during the harvesting configuration of the harvester shownin FIG. 6A, according to some embodiments.

FIG. 7A is a simplified general block diagram illustrating a suspensionsystem during a transition configuration of a harvester, according tosome embodiments.

FIG. 7B is a simplified general block diagram illustrating a front viewof a header during the transition configuration of the harvester shownin FIG. 7A, according to some embodiments.

FIG. 8A is a simplified general block diagram illustrating a suspensionsystem during a non-harvesting transport configuration of a harvester,according to some embodiments.

FIG. 8B is a simplified general block diagram illustrating a front viewof a header during the non-harvesting transport configuration of theharvester shown in FIG. 8A, according to some embodiments.

FIG. 9A is a simplified general block diagram illustrating a suspensionsystem during a downward flex configuration of a harvester, according tosome embodiments.

FIG. 9B is a simplified general block diagram illustrating a front viewof a header during the downward flex configuration of the harvestershown in FIG. 9A, according to some embodiments.

DETAILED DESCRIPTION

Referring generally to the FIGURES, a suspension system 200 for aharvester 100 configured to reduce structural loads is shown. As will bedescribed in more detail below, suspension system 200 is configured as avariable spring rate suspension system, which allows the header 104 tomore closely and easily follow terrain while the harvester 100 is in aharvesting mode, while also providing the header 104 with the ability toflex during an elevated, non-harvesting transport configuration of theheader 104. In doing so, the suspension system 200 reduces thestructural loads that the combine 102 supporting the header 104 issubject to during operation of the harvester 100. As such, thesuspension system 200 allows the width of the header 104 to be increased(so as to, e.g., increase harvesting throughput) without requiringreinforcement of the structure of the combine 102 to support theincreased mass of the wider header 104.

Referring to FIGS. 1A-1C, an agricultural harvester 100 according to oneembodiment is shown in various harvesting configurations as theharvester 100 travels over terrain having varying contours. Asillustrated in FIGS. 1A-1C, according to various embodiments, theharvester 100 includes a combine 102 and an agricultural harvestingheader 104 supported on the front of the combine 102.

As illustrated by the simplified block diagram of FIG. 2, according tovarious embodiments, the header 104 defines an articulated structurecomprising a center section 142 to which a left wing 144 a is hingedlyconnected by a left hinge joint 146 a and to which a right wing 144 b ishingedly connected by a right hinge joint 146 b. The connection of theleft wing 144 a to the center section 142 via left hinge joint 146 aallows the left wing 144 a to pivot upwards or downwards relative to thecenter section 142 about a generally horizontal axis along which theleft hinge joint 146 a extends. Similarly, the connection of the rightwing 144 b to the center section 142 via right hinge joint 146 b allowsthe right wing 144 b to pivot upwards or downwards relative to thecenter section 142 about a generally horizontal axis along which theright hinge joint 146 b extends. As will be understood, given theindependent hinged attachment of each of the left wing 144 a and theright wing 144 b to the center section 142, the left wing 144 a maypivot in any direction (i.e. upwardly or downwardly) and to any degree,irrespective of any pivoting of the right wing 144 b about the centersection 142, and vice versa.

Although, as described below, the harvester 100 comprises a suspensionsystem 200 configured to maintain the header 104 in a generally flatconfiguration, according to some embodiments, such as, e.g., illustratedin FIG. 2, a manually or automatically actuated lock 148 may be providedbetween left wing 144 a and center section 142 and/or between right wing144 b and center section 142 which may optionally be used in situationsin which a user may desire to fixedly and rigidly restrain the pivotingmovement of left wing 144 a and/or right wing 144 b relative to thecenter section 142.

As the harvester 100 transitions from travelling along generally flatterrain (during which the center section 142, left wing 144 a and rightwing 144 b each extend along a generally horizontal plane, such as,e.g., illustrated in FIG. 1A, that is substantially parallel to theterrain on which the header 104 is supported) to uneven terrain, thehinged connections of the left wing 144 a and right wing 144 b to thecenter section 142 allow the header 104 to more closely adapt to andconform to the contours of the variable terrain (such as, e.g.,illustrated in FIGS. 1B and 1C).

In addition to increasing crop yield, by allowing the left wing 144 aand right wing 144 b to independently flex and adapt to changingterrain, the mass of the header 104 that is accelerated as the header104 travels over uneven terrain is decreased, thereby minimizing thestructural loads on the combine 102. Thus, the articulated configurationof the header 104 allows the width of the header 104 to be increased (ascompared to a rigid, non-articulated header) without necessarilyresulting in increased stress on the combine 102, thereby obviating theneed to reinforce the combine 102 to support the wider width header 104.

The combine 102 generally includes a combine harvester vehicle 106 andfeederhouse 108 pivotally attached about a rear end to a lower portionof the combine harvester vehicle 106 (such as, e.g., to a chassis of theharvester vehicle 106). A forward end of the feederhouse 108 isconfigured to support the header 104. According to various embodiments,one or more feederhouse actuators (not shown) are operably coupledbetween the rear end of the feederhouse 108 and the combine harvestervehicle 106. The feederhouse actuators may comprise any number of knownactuator arrangements, with selective manual and/or automatic activationof the feederhouse actuator(s) being configured to cause the rear end ofthe feederhouse 108 to pivot relative to the combine harvester vehicle106, thereby resulting in a vertical movement of the forward end of thefeederhouse 108, as well as the resultant vertical movement of theattached header 104, in an upwards or downwards direction, such asillustrated, e.g., in FIG. 3.

As will be understood, the activation of these feederhouse actuators mayallow the harvester 100 to transition between a harvesting configurationin which the weight of the header 104 is at least partially supported bythe ground, to a non-harvesting transport configuration in which theheader 104 is elevated with reference to the ground (and in whichconfiguration the weight of the header 104 is supported entirely by thecombine 102), such as, e.g., illustrated in FIG. 3.

In light of the articulated configuration of the header 104, whenfeederhouse actuator(s) are activated to raise the header 104 to anelevated, non-harvesting transport configuration such as shown in FIG.3, the hinged attachment of left wing 144 a and right wing 144 b (“wings144”) to center section 142 via left hinge joint 146 a and right hingejoint 146 b, respectively, may cause the outermost ends of wings 144 tosag relative to the height of center section 142. As will be understood,the amount of downward displacement or sag of the outermost ends of thewings 144 as measured relative to the center section 142 increases asthe width of the wings 144 is increased.

As described above, the ability of wings 144 to pivot substantiallyrelative to center section 142 may advantageously allow the header 104to conform to the terrain during harvesting. However, such substantialpivoting movement of the wings 144 relative to the center section 142may be undesirable when the header 104 is in an elevated position (e.g.,when the harvester 100 is being turned around on end rows or duringnon-harvesting transport of the harvester 100). In particular, leavingthe wings 144 unsupported and free to pivot relative to center section142 while the header 104 is elevated may cause the outermost ends ofwings 144 to fully lower, thereby decreasing clearance to the groundeven when the header 104 is in a fully raised configuration, which mayallow inadvertent contact between the ground and header 104 that coulddamage the header 104.

Although preventing sagging of the outermost ends of the wings 144 inorder to maintain a substantially flat profile of the header 104 may bedesirable when the header 104 is in an elevated configuration such as,e.g., illustrated in FIG. 3—for reasons as described with reference torigid frame, non-articulated headers above—it may be undesirable to lockor otherwise fix the wings 144 into a substantially rigid configurationin an attempt to prevent the outermost ends of wings 144 from doing so.In particular, locking or otherwise restricting movement of the wings144 relative to the center section 142 during an elevated configurationof the header 104 (such as, e.g., during non-harvesting transport of theharvester 100) may undesirably increase the dynamic loads that areimparted by the header 104 onto the combine 102.

Instead, as will be described in more detail below, the harvester 100 isadvantageously provided with a suspension system 200 that allows forsome degree of pivoting movement of the wings 144 of the header 104relative to the center section 142 while also supporting the header 104in a substantially flat profile during field transport of the harvester100 (i.e. when the header 104 is lifted entirely off of the ground). Indoing so, the suspension system 200 minimizes the amount of header 104inertia that must be accelerated when encountering bumps in terrain,thereby reducing the forces imparted on the combine 102 during travel ofthe harvester 100 with the header 104 in an elevated configuration.

Accordingly, in various embodiments, the harvester 100 is provided witha variable spring rate suspension system 200 (FIG. 2) configured to becapable of being operated in a transport mode providing an increaseddegree of resistance to the displacement of the wings 144 relative tothe center section 142 when the header 104 is in an elevatedconfiguration (so as to, e.g., minimize or prevent the amount ofdownward displacement of the outermost ends of the wings 144 duringnon-harvesting transport of the harvester 100) and a harvesting modeproviding a decreased degree of resistance to the displacement of thewings 144 relative to the center section 142 when the header 104 is in aharvesting configuration, so as to allow the hingedly attached wings 144to pivot as needed relative to the center section 142 while theharvester 100 is in a harvesting configuration (i.e. when the header 104is at least partially supported along the ground), thus minimizing thestructural loading of the combine 102 by the header 104. As such, thesuspension system 200 may allow the harvester 100 to incorporate a widerheader 104 for more efficient harvesting throughput without requiring areinforced combine 102 structure to support the wider width header 104.

According to various embodiments, when the harvester 100 is in aharvesting configuration (i.e. when the header 104 is at least partiallysupported by the ground, such as, e.g., illustrated in FIGS. 1A-1C) andthe suspension system 200 is engaged in the harvesting mode, thesuspension system 200 of the harvester 100 may exhibit a degree ofstiffness that is configured to allow for upward and downward pivotingof the wings 144 by approximately no more than ±20.0°, more specificallyby approximately no more than ±10.0°, and more specifically byapproximately no more than ±5.0° as measured relative to the lateralaxis along which the center section 142 extends. When the harvester 100is an elevated, non-harvesting transport position (i.e. when the header104 is elevated such that the mass of the header 104 is not supported bythe ground) and the suspension system 200 is engaged in the transportmode, the degree stiffness of the suspension system 200 may be greateras compared to the stiffness characterizing the suspension system 200 inthe harvesting mode, such that the upwards or downwards pivoting of thewings 144 is constrained to between approximately 10% and 30%, morespecifically between approximately 15% and 25%, and even morespecifically approximately 20% of the range through which the wings 144are allowed to pivot when the harvester 100 is in the harvestingconfiguration. According to various embodiments, the upward and downwardpivoting of the wings 144 as measured relative to the lateral axis alongwhich the center section 142 extends is approximately no more than±15.0°, more specifically is no more than approximately ±7.5°, and evenmore specifically no more than approximately ±5.0° when the harvester100 is in a non-harvesting transport position (such as, e.g.,illustrated in FIG. 3). By defining differing suspension spring rates ineach of the harvesting and non-harvesting transport modes, thesuspension system 200 is configured to allow for between anapproximately 10% to approximately 20% reduction in the stress impartedonto the combine 102 by the articulated header 104, as compared to thestructural load that would be imparted by a rigid, non-articulatedheader 104 having a similar width and mass.

As will be understood, the suspension system 200 may be defined by anynumber of and combination of different components that are arranged in amanner to allow for the selective change in spring rate of thesuspension system 200 in the different operating modes, so as to, e.g.,allow for the selective constraint of the movement of the wings 144relative to the center section 142 according to first and secondvariable states. In particular, in a first variable state correspondingto the harvesting mode, the suspension system 200 is defined by a firststiffness that may, according to some embodiments, be configured suchthat movement of the wings 144 is constrained to a first range (such as,e.g., described with reference to the harvesting configuration above).Meanwhile, in a second variable state corresponding to a transport mode,the suspension system 200 is defined by a second stiffness that may,according to some embodiments, be configured such that movement of thewings 144 is constrained to a second range that is less than the firstrange (such as, e.g., described with reference to the non-harvestingtransport configuration above).

For example, according to some embodiments, suspension system 200 maycomprise a first set of coiled springs 202 a positioned about the leftwing 144 a and a second set of coils positioned about right wing 144 b.Each of the first set and second set of coiled springs comprise a firstspring 203 a-b and a second spring 205 a-b. One or both of the length ofthe first spring 203 a-b and/or spring constant of the first spring 203a-b differs from the second spring 205 a-b, such that the spring forceof the first spring 203 a-b is greater than the spring force of thesecond spring 205 a-b. The first and second springs 203 a-b and 205 a-bare configured to be independently engageable, such that, when thesuspension system 200 is operated in the transport mode, the firstspring is engaged 203 a-b, and the stiffness of the suspension system200 is increased as compared to the stiffness of the suspensions system200 during operation in the harvesting mode. Accordingly, in thetransport mode the pivoting movement of the wings 144 about centersection 142 of the header 104 may be constrained to a smaller range ofmotion than when the suspension system 200 is operated in the harvestingmode in which the first spring 203 a-b is disengaged, and the secondspring is engaged 205 a-b.

Accordingly, in such embodiments, by selectively engaging the secondsprings, the decreased spring rate of the suspension system 200 in theharvesting mode may provide the wings 144 with sufficient ability topivot about center section 142 so as to allow the wings 144 to adapt tothe contours of changing terrain when the harvester 100 is in harvestingposition. Meanwhile, by selectively engaging the first springs 203 a-b,the increased spring rate of the suspension system 200 in thenon-harvesting transport mode may be configured to result in a moreconstrained movement of the wings 144 relative to the center section142, thereby minimizing the degree of displacement of the outermost endsof the wings 144 relative to the center section 142 (and therebyminimizing the risk of the outermost ends inadvertently contacting theground when the header 104 is in an elevated, transport position) whilealso providing the wings 144 with sufficient flexibility to pivot so asto minimize the dynamic loads on the combine 102 during non-harvestingtransport of the harvester 100 (such as, e.g., illustrated in FIG. 3).

Alternatively, in other coiled spring embodiments of suspension system200, a single coiled spring may be positioned about each of the leftwing 144 a and the right wing 144 b. The suspension system 200 mayfurther comprise a length adjusting mechanism associated with each ofthe left wing 144 a and right wing 144 b, which is selectivelyactuatable to increase or decrease the effective length of the coiledspring. During non-harvesting transport with the header 104 in anelevated transport position, the length adjusting mechanisms may beactuated to effectively shorten the lengths of the springs, therebyincreasing the spring rate of the springs (and resultant stiffness ofthe suspension system 200) and thereby increasing the resistance to themovement of the wings 144 relative to center section 142. Meanwhile,engagement of the harvesting mode of the suspension system 200 may causethe length adjusting mechanisms to be actuated to effectively lengthenthe springs, thereby decreasing the spring rate of the springs (andresultant stiffness of the suspension system 200) and thereby decreasingthe degree of resistance to the movement of the wings 144 relative tothe center section 142. As will be understood, according to variousembodiments, the length adjusting mechanisms may be configured to allowthe effective lengths of the springs to vary between first and secondfixed lengths, while in other embodiments, the length adjustingmechanisms may be configured to allow the effective lengths of thesprings to be varied as desired, thus allowing for greater or lesserdegrees of constraint of the movement of the wings 144 relative to thecenter section 142 of the header 104 during different non-harvestingtransport and/or harvesting uses of the harvester 100. Additionally,while in some such embodiments the length adjusting mechanisms of thewings 144 may be actuated by the suspension system 200 in tandem withone another, in other embodiments, the length adjusting mechanisms maybe actuated independent of one another, such that the degree to whichmovement of the left wing 144 a is constrained may vary from the degreeto which movement of the right wing 144 b is constrained, and viceversa.

According to other embodiments, the suspension system 200 mayalternatively, or additionally, comprise one or more elements (such as,e.g., variable length legs) that may be selectively engaged and/oractuated to physically constrain the degree to which the wings 144 maydeflect upwards and/or downward to a predetermined range of motionand/or block the wings 144 from deflecting upwards and/or downwards pasta predetermined distance during different operational modes of theharvester. In some such embodiments, such physicallyconstraining/blocking elements may be used in conjunction with thefeatures of to any of variable spring rate suspension system 200embodiments described herein. Alternatively, in other such embodimentsin which the suspensions system 200 includes such constraining/blockingelement, the suspension system 200 may be defined by a single fixedspring rate during operation of the harvester 100 according to any ofthe various operational modes of the harvester 100.

In yet other embodiments, the suspension system 200 may comprise ahydraulic system configured to provide for first and second variablestates corresponding to the harvesting and non-harvesting transportmodes of the suspension system 200 which selectively allow for differingdegrees of resistance to the pivoting of the wings 144 relative to thecenter section 142. For example, in some embodiments (not shown), thesuspension system 200 may comprise a pair a hydraulic circuits that areoperably provided for each of the left wing 144 a and right wing 144 b,with a first circuit having a different volume and/or pressure of fluidthan a second, distinct circuit defining the pair of hydraulic circuits,such that the suspensions system 200 is defined by differing degrees ofstiffness depending on which hydraulic circuit the suspension system 200is fluidly engaged to.

Referring to FIG. 4, a simplified schematic of a hydraulic based springsuspension system 200 comprising a blocker valve 300 which is configuredto provide for first and second variable states corresponding toharvesting and non-harvesting transport modes of the suspensions system200, respectively, according to one embodiment is illustrated. Thesuspension system 200 illustrated in FIG. 4 corresponds to a springsuspension system 200 configured for use with one of the left wing 144 aor right wing 144 b of the header 104, with the other of the left wing144 a or right wing 144 b being provided with a substantially similar,albeit mirrored, suspension system 200 as shown in and described withreference to FIG. 4.

Suspension system 200 generally comprises a fluid cylinder 202 that isfluidly connected to one or more accumulators 206 via an attenuationhose 208. The accumulators 206 are configured to store a volume ofpressurized fluid (such as, e.g., incompressible hydraulic fluid) thatis supplied to the fluid cylinder 202 via the attenuation hose 208. Asfluid flows into or out from the fluid cylinder 202, the fluid cylinder202 is configured to extend or retract. As the fluid cylinder 202 isconfigured to suspend the wing 144, the retraction and extension of thefluid cylinder 202 in response to changes in the amount of fluid withinfluid cylinder 202 causes the wing 144 to move pivotally about thecenter section 142, resulting in the upward or downward movement of thewing 144 relative to the center section 142.

A blocker valve 300 is fluidly disposed between the fluid cylinder 202and the accumulators 206. As will be described with more detail withreference to FIGS. 6A-9B below, the blocker valve 300 is configured toallow for selective flow of fluid between the fluid cylinder 202 and theaccumulators 206, allowing the fluid cylinder 202 to provide varyingdegrees of suspension of the wing 144, which in turn allows thesuspension system 200 to provide for first and second variable states inwhich the suspension system 200 is defined having differing stiffnessesthat selectively allow for differing degrees of resistance to thepivoting of the wings 144 relative to the center section 142 duringharvesting and non-harvesting transport of the harvester 100.

As shown in FIG. 6A, the accumulators 206 are additionally fluidlyconnected to a hydraulic block 210, which serves as a source of fluidfor the accumulators 206. Fluid from the hydraulic block 210 is suppliedto the accumulators 206 in response to the selective activation of avalve 212 to permit flow between the hydraulic block 210 andaccumulators 206. Once sufficient fluid has been allowed to fill theaccumulators 206 to a desired pressure, the valve 212 may be activatedto a closed configuration. As will be understood, according to someembodiments, a single hydraulic block 210 may be common to thesuspension systems 200 of both the left wing 144 a and the right wing144 b, while in other embodiments, the suspension systems 200 of each ofthe left wing 144 a and the right wing 144 b may comprise distinct,individual hydraulic blocks 210.

Referring to FIGS. 5A-5C, a blocker valve 300 according to variousembodiments is illustrated. In general, the blocker valve 300 isselectively actuatable between a flow position, defined by a flowstructure 302 and a restricted flow position defined by aflow-restriction structure 304. As will be understood, blocker valve 300may be biased to either the flow position or restricted-flow position,and may be selectively energized or otherwise activated between the flowand restricted flow positions according to any number of differentarrangements, including mechanical and/or electromechanicalarrangements.

Additionally, while in some embodiments the activation of the blockervalve 300 between the flow position and the restricted-flow position maybe controlled directly by the operator as desired, according to otherembodiments, the activation of the blocker valve 300 may be controlledby a control system of the harvester 100. For example, according to someembodiments, the harvester 100 may comprise a control system, which, inaddition to controlling other aspects of the operation of the harvester100, may additionally be configured to control the activation of theblocker valve 300. According to some such embodiments, the controlsystem may be configured to automatically activate the blocker valve 300to the restricted-flow position upon the control system exiting out ofan auto-header height mode of the control system and/or in response tothe feederhouse 108 (and attached header 104) being lifted up andelevated with respect to the ground. In yet other embodiments, thecontrol system may be configured such that, when the harvester 100 isoperated in a manual mode, the blocker valve 300 is automaticallyactivated to a restricted-flow position upon the control systemreceiving a signal from ground detection sensors that the header 104 hasbeen elevated off of the ground.

When the blocker valve 300 is in the restricted-flow position, fluidpresent within the fluid cylinder 202 and attenuation hose 208 isprevented from flowing into the accumulators 206. However, according tosome embodiments, it may be advantageous to allow for a limited degreeof fluid flow from the accumulators 206 into the attenuation hose 208and fluid cylinder 202. Accordingly, as shown in FIG. 5A, according tosome embodiments, the flow-restriction structure 304 of blocker valve300 may comprise an orificed check valve structure 400, which isconfigured to restrict flow from the attenuation hose 208 and fluidcylinder 202 into the accumulators 206, but which allows for flow fromthe accumulators 206 into the attenuation hose 208, even when theblocker valve 300 is in the restricted flow position.

In other embodiments, it may be desired that there be no flow in eitherdirection (i.e. no flow of fluid into or out of the accumulators 206)when the blocker valve 300 is in the restricted flow position. Accordingto some such embodiments, the flow-restriction structure 304 of blockervalve 300 may comprise a double-checked valve structure (such as, e.g.,illustrated in FIG. 5B) or other structure configured to prevent flow ineither direction through the blocker valve 300.

As shown in FIG. 5C, in some embodiments in which the blocker valve 300comprises a flow-restriction structure 304 configured to prevent flow ineither direction through the blocker valve 300 (such as, e.g., adouble-checked valve flow-restriction structure 304), the suspensionsystem 200 may include an orificed check valve structure 400 arrangedfluidly in parallel with the blocker valve 300. By providing analternate fluid path through which fluid from the accumulators 206 mayflow into the attenuation hose 208, the orificed check valve structure400 may allow for restricted flow of fluid from the accumulators 206into the attenuation hose 208 even when the blocker valve 300 is in therestricted-flow position.

The ability of the suspension system 200 to provide for first and secondvariable states which selectively allow for differing degrees ofpivoting of the wings 144 relative to the center section 142 will now bedescribed with reference to FIGS. 6A-9B.

Referring to FIGS. 6A and 6B, a simplified block diagram of thesuspension system 200 and the header 104 configuration is shown duringharvesting operation of the harvester 100 according to some embodiments.As described above, during harvesting, the articulated configuration ofheader 104 (in which left wing 144 a is hingedly attached to centersection 142 via a left hinge joint 146 a and in which right wing 144 bis hingedly attached to center section 142 via a right hinge joint 146b) allows the wings 144 of the header 104 to pivot upward and/ordownward relative to the center section 142 to allow the header 104 tomore closely follow the contours of the terrain.

As shown in FIG. 6A, to facilitate the ability of the wings 144 totravel over and follow contours in terrain during harvesting operation,the blocker valve 300 is in a flow configuration during the harvestingmode of the suspension system 200, in which the flow structure 302 ofthe blocker valve 300 is aligned between the accumulators 206 and theattenuation hose 208 so as to allow fluid to freely flow between theaccumulators 206 and fluid cylinder 202. As described above, by allowingfluid to flow into and out from the fluid cylinder 202 the fluidcylinder 202 is able to extend and retract as needed in response tochanges in terrain. As will be understood, according to variousembodiments, a float system configured to assist the header 104 inadapting to changes in terrain (such as, e.g., by monitoring changes inpressure imparted onto the header 104 and assisting in the flow of fluidinto and out from the fluid cylinder 202 so as to maintain a desiredtarget pressure) may be incorporated into harvester 100.

Because fluid is allowed to flow freely between the accumulators 206 andfluid cylinder 202 during harvesting operation of the device, thepressure within the attenuation hose 208 will be substantially the sameas the pressure within the accumulators 206. The simplified blockdiagram of FIG. 6B illustrates the header 104 when the header 104 ispositioned on substantially flat terrain, and as such, the entire header104 is shown in FIG. 6B as extending in a generally planar manner.However, as will be understood, if the simplified block diagram of FIG.6B were to represent the header 104 along uneven terrain, the wings 144of header 104 would be shown as extending substantially parallel to theterrain above which the wings 144 extended, such that the wings 144would extend at non-zero degree angles relative to the center section142.

Referring to FIG. 7A, a simplified diagram of the suspension system 200according to one embodiment is illustrated representative of atransition configuration of the harvester 100, in which the header 104is still supported by the ground (i.e. the header 104 has not beenelevated to a point where the combine 102 supports the entirety of theweight of the header 104) and in which the blocker valve 300 has beendeenergized or otherwise deactivated from the flow position to therestricted-flow position.

In the transition configuration, the switching of the blocker valve 300into the restricted-flow position prevents any fluid from flowing intoor out from the accumulators 206. Upon entering into the transitionconfiguration, the amount of fluid within the fluid cylinder 202 andattenuation hose 208 corresponds to the amount of fluid that had beenpresent within the fluid cylinder 202 and attenuation hose 208immediately prior to the blocker valve 300 being switched to therestricted-flow position. Accordingly, upon entering the transitionconfiguration (i.e., upon initiation of the non-harvesting transportmode of the suspensions system 200), the wings 144 are ‘locked’ in theirlast position prior to the harvester 100 being put into the transitionconfiguration. The ‘locked’ configuration of the wings 144 maycorrespond to a configuration of the wings 144 in which one or both ofthe wings 144 extend angled upward relative to center section 142,extend angled downward relative to center section 142, and/or extendsubstantially parallel to center section 142. As will be understood, theconfiguration of the wings 144 in the ‘locked’ position will depend onwhether the fluid cylinder 202 was in a retracted, expanded, or neutralstate immediately prior to switching the blocker valve 300 into therestricted-flow configuration.

As illustrated in FIG. 7B, because the header 104 remains partiallysupported by the ground in the transition configuration, the wings 144of the header 104 remain extending in a direction substantially parallelto the terrain above which the wings 144 are supported. As similarlydescribed with reference to FIG. 6B, the header 104 that is representedby the simplified block diagram of FIG. 7B is shown in a configurationin which the header 104 is positioned atop substantially horizontalterrain. However, as will be understood, if the simplified block diagramof FIG. 7B were to represent the header 104 positioned along uneventerrain, the wings 144 of header 104 would be shown as extendingsubstantially parallel to the surface above which the wings 144 extend,such that the wings 144 would extend at non-zero degree angles relativeto the center section 142.

Referring to FIG. 8A, a simplified block diagram representative of thesuspension system 200 during non-harvesting transport of the harvester100 with the header 104 in an elevated position in which the weight ofthe header 104 is entirely supported by the combine 102 is shownaccording to one embodiment. As shown in FIG. 8A, in such an elevated,non-harvesting configuration of the header 104, the blocker valve 300remains closed in a restricted-flow configuration, in which flow offluid from the fluid cylinder 202 and attenuation hose 208 into theaccumulators 206 is prevented. According to various embodiments, inorder to decrease the degree of stiffness of the suspension system 200when in the non-harvesting mode, the attenuation hose 208 may beconstructed with a desired degree of elasticity and resilience, whichallows the attenuation hose 208 to expand to hold increased volumes offluids as compared to an initial, neutral configuration of theattenuation hose 208. Although the flow of fluid into the accumulators206 is prevented by the blocker valve 300, fluid is free to flow betweenthe fluid cylinder 202 and attenuation hose 208 during the elevated,non-harvesting transport configuration of the header 104. As such, whenthe header 104 is elevated, causing the wing 144 to no longer besupported the ground, the elastic nature of the attenuation hose 208 isconfigured to allow some, or all, of the fluid that was ‘locked’ in thefluid cylinder 202 during the transition configuration (as describedwith reference to FIGS. 7A and 7B above) to flow into the attenuationhose 208, thereby increasing the volume of ‘locked’ fluid alreadypresent within the attenuation hose 208 (as also described withreference to FIGS. 7A and 7B above).

As representatively illustrated by the simplified block diagram of FIG.8A, the displacement of some or all of the fluid from the fluid cylinder202 into the attenuation hose 208 increases the pressure of the fluidwithin the attenuation hose 208 to a pressure that is greater than thepressure of the fluid stored within the accumulators 206. Meanwhile, asrepresentatively illustrated by the simplified block diagram of FIG. 8B,the decrease in the volume of fluid within the fluid cylinder 202resulting from the displacement of fluid from the fluid cylinder 202into the attenuation hose 208 decreases the ability of the fluidcylinder 202 to suspend the wing 144, which in turn causes the wing 144to pivot downward relative to the center section 142 by an angle of alfrom an initial wing 144 position defined by the position of the wing144 in the transition configuration (which in turn, corresponds to lastposition of the wing 144 during the last harvesting configuration of theheader 104 prior to the blocker valve 300 being switched to arestricted-flow position).

According to various embodiments, the angle αl may range fromapproximately 0.05° to 1.5°, more specifically between approximately0.5° and 1.0°, and even more specifically between approximately 0.6° and0.8°. As will be understood, the angle αl by which the left wing 144 ais pivoted downwards relative to the center section 142 during theelevated, non-harvesting transport configuration may be the same or maybe different than the angle αl by which the right wing 144 b is pivoteddownwards relative to the center section 142 during the elevated,non-harvesting transport configuration.

Although, as shown in FIG. 8B, the wings 144 of the header 104 willexhibit some degree of sagging (i.e. pivoting of the wings 144 downwardsrelative to the center section 142), with respect to the initialposition of the wings 144 as defined by the position of the wings 144during the transition configuration, the position of the wings 144during the elevated, non-harvesting transport configuration may extendat an upwards angle relative to the center section 142, generally planarwith the center section 142, or at a downwards angle relative to thecenter section 142. As will be understood, the angle(s) relative to thecenter section 142 at which the wings 144 extend during the elevated,non-harvesting transport configuration will depend on factors includingthe angle(s) of the wings 144 relative to the center section 142 duringthe last harvesting configuration of the header 104 prior to the blockervalve 300 being switched to a restricted-flow position as well as theangle(s) α1 by which the wings 144 are pivoted downwards during theelevated, non-harvesting transport configuration.

According to various embodiments, as the harvester 100 is in theelevated, non-harvesting transport configuration (such as, e.g.,represented in FIGS. 8A and 8B), the harvester 100 may transition to adownward flex configuration in response to the mass of the header 104being subject to a downwards acceleration force (such as, e.g., inresponse to the harvester 100 travelling over uneven terrain). Asillustrated in FIG. 9A, during such additional loading of the header 104in the downward flex configuration, additional fluid flows out of thefluid cylinder 202 and into the attenuation hose 208. This additionalfluid causes the volume of fluid within the attenuation hose 208 tofurther increase from the increased volume that the attenuation hose 208was subject to during the elevated, non-harvesting transportconfiguration. As shown in FIG. 9A, as a result of this additional fluidnow held within the attenuation hose 208, the pressure within theattenuation hose 208 is further increased.

Meanwhile, as representatively illustrated by the simplified blockdiagram of FIG. 9B, the additional decrease in the volume of fluidwithin the fluid cylinder 202 as fluid is displaced from the fluidcylinder 202 and into the attenuation hose 208 during the downward flexconfiguration causes the wing 144 to pivot further downwards relative tothe center section 142 by an angle of α2. According to variousembodiments, the angle α2 may range from approximately 0.05° toapproximately 2.0°, more specifically between approximately 0.5° andapproximately 1.5°, and even more specifically by approximately 1.0°. Aswill be understood, the angle α2 by which the left wing 144 a is pivoteddownwards relative to the center section 142 during the downward flexconfiguration may be the same or may be different than the angle α2 bywhich the right wing 144 b is pivoted downwards relative to the centersection 142 during the downward flex configuration.

As explained with reference to FIG. 8B, although, as shown in FIG. 9B,the wings 144 of the header 104 will exhibit some degree of sagging(i.e. pivoting of the wings 144 downwards relative to the center section142), with respect to the position of the wings 144 in the configurationimmediately prior to the downward flex configuration of the header 104(such as, e.g., the elevated, non-harvesting transport configuration ofFIGS. 8A and 8B), the position of the wings 144 during the downward flexconfiguration may extend at an upwards angle relative to the centersection 142, generally planar with the center section 142, or downwardsrelative to the center section 142. As will be understood, the angle(s)relative to the center section 142 at which the wings 144 extend duringthe downward flex configuration will depend on factors such as, e.g.,the angle(s) of the wings 144 relative to the center section 142 duringthe last harvesting configuration of the header 104 prior to the blockervalve 300 being switched to a restricted-flow position; the angle(s) alby which the wings 144 are pivoted downwards during the elevated,non-harvesting transport configuration; the angle(s) α2 by which thewings 144 are pivoted downwards during the downward flex configuration;etc.

As illustrated by FIGS. 6A-9B, the ability of the blocker valve 300 toisolate flow into the accumulators 206 during a restricted-flow positionand to allow flow to and from the accumulators 206 during a flowposition provides the suspension system 200 with first and secondvariable states defined by varied spring rates, which selectivelyprovide differing degrees of resistance to the movement of the wings144, and thus allow for differing degrees of pivoting of the wings 144relative to the center section 142. As discussed with reference to FIGS.6A and 6B, when the blocker valve 300 is in the flow position, the firstvariable state (i.e. the harvesting mode) is defined by the hydrauliccircuit defined between the fluid cylinder 202, the accumulators 206,and the attenuation hose 208. In this first variable state, the abilityof fluid to flow freely between the fluid cylinder 202 and theaccumulators 206 provides the hydraulic circuit with a relatively lowstiffness, and thus allows the wings 144 to pivot about the centersection 142 by an amount that defines a first range of motion. Byallowing the wings 144 to pivot about the center section 142, thesuspension system 200 enables the wings 144 to dynamically adapt to andfollow terrain, which, in addition to increasing crop yield efficiency,also reduces the dynamic loads on the harvester 100 during harvestingoperation.

As discussed with reference to FIGS. 7A-9B, when the blocker is in therestricted-flow position, the second variable state (i.e. the transportmode) is defined by the hydraulic circuit defined between the fluidcylinder 202 and the attenuation hose 208. In the second variable state,the expandable nature of the attenuation hose 208 allows the attenuationhose 208 to hold fluid that may flow out of the fluid cylinder 202. Thisability of the attenuation hose 208 to hold an increased capacity offluid provides the suspension system 200 with a manner by which thewings 144 are provided with a second range of motion by which the wings144 may pivot relative to the center section 142. However, overall, thehydraulic circuit in the transport mode is defined by a greater springrate than when in the harvesting mode, and accordingly movement of thewings 144 relative to the center section 142 is subject to an increasedresistance that results in the movement of the wings 144 being limitedto a smaller range of motion than in the first state.

Because the second range of motion is smaller than the first range ofmotion (such as, e.g., by between approximately 10% and approximately30%), the ability of the wings 144 to pivot about the center section 142is more limited when the suspension system 200 is in the second variablestate than when the suspension system 200 is in the first variablestate. As such, when the header 104 is elevated from the ground with thesuspension system 200 in the second variable state (such as, e.g.,discussed with reference to the elevated, non-harvesting transportconfiguration shown in FIGS. 8A and 8B) the suspension system 200 isconfigured to maintain the header 104 in a relatively levelconfiguration in which the header 104 only exhibits a minimum amount ofsagging, thus minimizing the risk of the outermost ends of the wings 144inadvertently coming into contact with the ground during non-harvestingtransport of the harvester 100.

Although the range of motion through which the wings 144 are able topivot in the second variable state is limited, by providing even alimited range of motion by which the wings 144 are able to pivot aboutthe center section 142, (such as, e.g., by a range of betweenapproximately ±0.05° and approximately ±2.0°) the suspension system 200is able to reduce the mass of the header 104 that is accelerated duringtransport of the harvester 100 (such as, e.g., while the harvester is anthe elevated, non-harvesting transport configuration), thereby reducingthe stress on the structure of the combine 102 (such as, e.g., by atleast approximately 5%).

As noted above, the ability of the suspension system 200 to provide thewings 144 with a limited ability to flex while the suspension system 200is in the second variable state is provided by the ability of theattenuation hose 208 to hold fluid that flows out from the fluidcylinder 202 when the wings 144 are subject to downward forces (such as,e.g., when the header 104 is elevated entirely off of the ground in theelevated, non-harvesting transport configuration or during the downwardflex configuration in which the harvester 100 travelling with anelevated header 104 encounters uneven terrain). Accordingly, as will beunderstood, in various embodiments, the range of motion through whichthe wings 144 are able to pivot while the suspension system 200 is inthe second variable state may be varied by changing any number ofvariables that would affect the spring constant of the hydraulic circuitin the transport mode, such as, e.g., changing the length of theattenuation hose 208, changing the selection of materials and/orstructure of the attenuation hose 208 (to either make the attenuationhose 208 more or less compressible), etc. Additionally, according tosome embodiments, the suspension system 200 may optionally be providedwith an additional structure via which fluid may be added to and/orremoved from the circuit defined by the fluid cylinder 202 and theattenuation hose 208 when the suspension system 200 is in the secondvariable state.

As will be understood, although the harvesting configuration of FIGS. 6Aand 6B, the transition configuration of FIGS. 7A and 7B, the elevated,non-harvesting transport configuration of FIGS. 8A and 8B, and thedownward flex configuration of FIGS. 9A and 9B have been described asoccurring in a sequential manner, as will be understood, the variousconfigurations illustrated and described with reference to FIGS. 6A-9Bmay occur according to any other number of sequences, in which any ofthe configurations may be repeated any number of different times.Additionally, the header 104 may be subject to the configurations ofFIGS. 6A-9B for varied durations of time. For example, according tovarious embodiments, the downward flex configuration of FIGS. 9A and 9Bmay directly follow the transition configuration of FIGS. 7A and 7B. Insome embodiments, the transition configuration of FIGS. 7A and 7B maydirectly follow the elevated, non-harvesting transport configuration ofFIGS. 8A and 8B.

As will also be understood, although the articulated header 104illustrated herein has been shown as comprising three sections: a centersection 142, a left wing 144 a, and a right wing 144 b, according toother embodiments, the articulated header 104 may comprise any number ofdifferent sections, including, e.g., a two section arrangement definedby only the left wing 144 a and the right wings 144 b.

The construction and arrangement of the systems and methods as shown inthe various exemplary embodiments are illustrative only. Although only afew embodiments have been described in detail in this disclosure, manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters, mounting arrangements, use of materials, colors,orientations, etc.). For example, the position of elements may bereversed or otherwise varied and the nature or number of discreteelements or positions may be altered or varied. Accordingly, all suchmodifications are intended to be included within the scope of thepresent disclosure. References herein to the positions of elements(e.g., “top,” “bottom,” “above,” “below,” “upper”, “lower”, etc.) aremerely used to describe the orientation of various elements in theFIGURES. It should be noted that the orientation of various elements maydiffer according to other exemplary embodiments, and that suchvariations are intended to be encompassed by the present disclosure.

The term “coupled,” as used herein, means the joining of two membersdirectly or indirectly to one another. Such joining may be stationary(e.g., permanent or fixed) or moveable (e.g., removable or releasable).Such joining may be achieved with the two members coupled directly toeach other, with the two members coupled to each other using a separateintervening member and any additional intermediate members coupled withone another, or with the two members coupled to each other using anintervening member that is integrally formed as a single unitary bodywith one of the two members. Such members may be coupled mechanically,electrically, and/or fluidly. The order or sequence of any process ormethod steps may be varied or re-sequenced according to alternativeembodiments. Other substitutions, modifications, changes, and omissionsmay be made in the design, operating conditions and arrangement of theexemplary embodiments without departing from the scope of the presentdisclosure.

We claim:
 1. A harvesting system comprising: an articulated headerdefined by at least a first section and a second section, the firstsection and second section being configured for independent pivotingmovement relative to one another; and a suspension system having a firstmode and a second mode, the suspension system being configured to allowpivoting movement of each of the first section and second section inboth the first mode and second mode; wherein in the first mode, thesuspension system is configured to restrict pivoting movement of thefirst section and second section by a first degree in response to thefirst section and second section being subject to a first force; andwherein in the second mode, the suspension system is configured torestrict pivoting movement of the first section and second section by asecond degree that is different than the first degree in response to thefirst section and second section being subject to a second force that issubstantially the same as the first force.
 2. The harvesting system ofclaim 1, wherein the header is configured to move between a firstposition in which at least a portion of the header is supported along aground surface and a second position in which the header is elevatedentirely off of the ground surface, the suspension system beingconfigured to operate in the first mode when the header is in the firstposition and to operate in the second mode when the header is in thesecond position.
 3. The harvesting system of claim 2, further comprisinga control system having an automatic header height control mode, thesuspension system being configured to automatically engage the secondmode in response to the header height control mode being deactivated. 4.The harvesting system of claim 2, wherein the suspension system isdefined by a first suspension stiffness during the first mode and asecond suspension stiffness during the second mode, the second stiffnessbeing different than the first stiffness.
 5. The harvesting system ofclaim 4, the suspension system comprising a first coiled spring and asecond coiled spring defined by a greater spring constant than a springconstant defining the first coiled spring, wherein the first coiledspring is engaged in the first mode of the suspension system and thesecond coiled spring is engaged in the second mode of the suspensionsystem.
 6. The harvesting system of claim 4, the suspension systemcomprising a coiled spring, wherein a length of the coiled spring isgreater in the first mode of the suspension system than a length of thecoiled spring in the second mode of the suspension system.
 7. Theharvesting system of claim 4, the suspension system comprising a fluidcylinder fluidly connected to an accumulator and a valve selectivelyopenable to permit flow between the fluid cylinder and the accumulator,wherein in the second mode, the valve is closed to block flow betweenthe fluid cylinder and accumulator.
 8. The harvesting system of claim 2,wherein the first section and second section are constrained by thesuspension system to a first range of pivoting movement in the firstmode and a second range of pivoting movement in the second mode, thesecond range being smaller than the first range.
 9. A method ofoperating a harvesting header comprising: operating a header comprisinga left wing and a right wing that are each hingedly attached to a centersection in a first position in which the header is at least partiallysupported by a ground surface, the degree to which the left wing and theright wing pivot upward or downward relative to the center section inresponse to being subject to a force being constrained to a firstoperating range when the header is in the first position by a suspensionsystem; and operating the header in a second position in which theheader is entirely elevated off of the ground surface, the degree towhich the left wing and the right wing pivot upward or downward relativeto the center section in response to being subject to a substantiallysimilar force being constrained to a second operating range by thesuspension system when the header is in the second position; wherein thefirst operating range is greater than the second operating range. 10.The method of claim 9, wherein the second operating range is greaterthan 0°.
 11. The method of claim 9, wherein the first operating rangecorresponds to a range that extends between approximately 10.0° upwardsand approximately 10.0° downwards as measured relative to the centersection.
 12. The method of claim 9, wherein the second operating rangeis approximately 20% of the first operating range.
 13. The method ofclaim 9, further comprising a variable spring suspension systemconfigured to selectively constrain the pivoting of the left wing andright wing relative to the center section to either the first operatingrange or the second operating range, wherein the variable springsuspension is defined by a first stiffness when operating the header inthe first position, and a second stiffness that is greater than thefirst stiffness when operating the header in the second position.
 14. Aharvester system comprising: a harvesting header comprising a firstsection and a second section, each of the first section and secondsection configured for independent pivoting movement; and a suspensionsystem operably connected to each of the first section and secondsection, the suspension system comprising: a first fluid cylindercoupled to the first section; a second fluid cylinder coupled to thesecond section; a first accumulator for the first cylinder; a secondaccumulator for the second cylinder; a first attenuation hose; a secondattenuation hose; and a first valve selectively openable to permit flowbetween the first attenuation hose and the first accumulator; and asecond valve selectively openable to permit flow between the secondattenuation hose and the second accumulator; wherein when the suspensionsystem is operated in a first mode, pivoting movement of each of thefirst section and second section is subject to a first degree ofresistance provided by the suspension system; wherein when thesuspension system is operated in a second mode, pivoting movement ofeach of the first section and second section is subject to a seconddegree of resistance provided by the suspension system that is differentthan the first degree of resistance; and wherein each of the firstsection and second section are capable of pivoting movement in each ofthe first mode and second mode.
 15. The harvester system of claim 14,wherein the valve is open during operation of the suspension system inthe first mode and is closed during operation of the suspension systemin the second mode, wherein the suspension system is defined having afirst stiffness in the first mode and a second stiffness, greater thanthe first stiffness, in the second mode.
 16. The harvester system ofclaim 15, wherein a channel extending through the attenuation hosedefines a first volume in the first mode and defines a second volumegreater than the first volume during at least a portion of operation ofthe suspension system in the second mode.
 17. The harvester system ofclaim 16, wherein a cross-sectional area of the channel is greaterduring the second mode than a cross-sectional area of the channel duringthe first mode.
 18. The harvester system of claim 15, further comprisinga fluid block, wherein the accumulator is fluidly connected to the fluidblock during at least the first mode.
 19. The harvester system of claim14, the harvesting head further comprising a center section to whicheach of the first section and second section are attached, each of thefirst section and second section independently pivoting relative to thecenter section.
 20. A harvester system comprising: a harvesting headercomprising a first section and a second section, each of the firstsection and second section being configured for independent pivotingmovement; and a suspension system operably connected to each of thefirst section and second section, the suspension system comprising: afirst fluid cylinder coupled to the first section; a second fluidcylinder coupled to the second section; a first accumulator for thefirst cylinder; a second accumulator for the second cylinder; a firstattenuation hose; a second attenuation hose; and a first valveselectively openable to permit flow between the first attenuation hoseand the first accumulator; and a second valve selectively openable topermit flow between the second attenuation hose and the secondaccumulator; wherein when the suspension system is operated in a firstmode, pivoting movement of each of the first section and second sectionis subject to a first degree of resistance; wherein when the suspensionsystem is operated in a second mode, pivoting movement of each of thefirst section and second section is subject to a second degree ofresistance that is different than the first degree of resistance; andwherein each of the first section and second section are capable ofpivoting movement in each of the first mode and second mode, wherein:the first accumulator is in fluid communication with the first fluidcylinder, and the second accumulator is in fluid communication with thesecond fluid cylinder; the first attenuation hose fluidly couples thefirst fluid cylinder and the first accumulator, and the secondattenuation hose fluidly couples the second fluid cylinder and thesecond accumulator.